How many user can be add in my yahoo messenger?

HI,I'm developing system for auto response people from yahoo chat room,(I use php to do it).so people add company yahoo id in their messengers or they enter their yahoo ids ,so system will add them.now I wanna know is there any limitation to add people?for example each account only can add 1000 ids as friends.and is there any limitation speed to add?for example I should add each yahoo id every 10 seconds?Please Provide This Info to me,tnx

HI,I'm developing system for auto response people from yahoo chat room,(I use php to do it).so people add company yahoo id in their messengers or they enter their yahoo ids ,so system will add them.now I wanna know is there any limitation to add people?for example each account only can add 1000 ids as friends.and is there any limitation speed to add?for example I should add each yahoo id every 10 seconds?Please Provide This Info to me,tnx